Process for applying noise-reducing elements to a tyre for vehicle wheels

ABSTRACT

A process for applying noise-reducing elements to a tyre for vehicle wheels. A plurality of noise-reducing elements are arranged on a feeding belt movable along a predetermined feeding direction. The noise-reducing elements are subsequently aligned along the feeding direction and brought into mutual contact, to then be transferred onto a service plane arranged downstream of the feeding belt along the feeding direction and having, on an upper surface thereof, a continuous film which supports a layer of adhesive material. The layer of adhesive material is applied onto a lower surface of each of the noise-reducing elements taking it from the continuous film. The noise-reducing elements are then transferred one by one onto a conveyor belt arranged downstream of the service plane along the feeding direction. The noise-reducing elements are finally positioned one by one on a radially inner surface of a tyre.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/340,642 filed on Apr. 9, 2019, which, in turn, is the U.S.National Stage Entry of International Patent Application No.PCT/IB2017/057318 filed on Nov. 22, 2017, which, in turn, claimspriority to Italian Patent Application No. 102016000117937 filed on Nov.22, 2016, which are all incorporated herein by reference in theirentirety.

DESCRIPTION

The present invention relates to a process and an apparatus for applyingnoise-reducing elements to a tyre for vehicle wheels.

Preferably, the process and the apparatus of the present invention allowan automatic or substantially automatic application of theaforementioned noise-reducing elements onto the tyre.

The term “automatic” is used to indicate an operation carried out bymechanical devices, without the need for manual intervention of anoperator.

The expression “mechanical devices” is used to indicate entirelymechanical, electro-mechanical, hydraulic or pneumatic devices, possiblycontrolled by a control unit through suitable software.

The expression “substantially automatic” is used to indicate that mostof the operations are carried out by the aforementioned mechanicaldevices and the manual intervention of an operator is limited to fewspecific operations. In the specific case of the present invention, themanual intervention of the operator is at most limited to the initialarrangement of the noise-reducing elements, for example to thepositioning of the noise-reducing elements on a conveyor belt.

The expression “noise-reducing element” is used to indicate an elementthat, upon being associated with a tyre for vehicle wheels, has thecapability to attenuate the noise produced by the tyre in use. Such acapability is preferably given to the aforementioned element by the typeof material which the aforementioned element is made from. A materialsuitable for this purpose is for example a sound-absorbing porousmaterial, like for example an expanded polymeric material, like forexample open-cell foamed polyurethane.

The term “elastomeric” is used to refer to a composition comprising atleast one elastomeric polymer and at least one reinforcing filler.Preferably, such a composition further comprises additives like, forexample, a cross-linking agent and/or a plasticizer. Thanks to thepresence of the cross-linking agent, such a material can be cross-linkedthrough heating, so as to form the final manufactured product.

The terms “radial” and “axial” and the expressions “radiallyinner/outer” and “axially inner/outer” are used referring to the radialdirection of the tyre (i.e. to a direction perpendicular to the rotationaxis of the tyre) and to the axial direction of the tyre (i.e. to adirection parallel to the rotation axis of the tyre). The terms“circumferential” and “circumferentially”, on the other hand, are usedreferring to the annular extension of the tyre.

The expression “feeding direction” is used to indicate a directionparallel to the longitudinal direction of a feeding belt. The feedingdirection thus corresponds to the advancing direction of the feedingbelt.

The expressions “low”, “below”, “lower” or “under”, and “high”, “over”,“upper” or “above” are used to indicate a relative position with respectto the aforementioned feeding belt.

The expressions “downstream” or “head”, and “upstream” or “tail” areused referring to the aforementioned feeding direction. Therefore,assuming for example a feeding direction from left to right, a“downstream” or “head” position with respect to any reference elementindicates a position at the right of said reference element and an“upstream” or “tail” position indicates a position at the left of saidreference element.

The operation through which two or more noise-reducing elements arebrought into mutual contact along said feeding direction is alsoidentified with the expression “compacting”.

A tyre for vehicle wheels generally comprises a carcass structurecomprising at least one carcass ply formed of reinforcing cordsincorporated in a matrix of elastomeric material. The carcass ply hasend edges respectively engaged with annular anchoring structures. Thelatter are arranged in the areas of the tyre usually identified with thename “beads” and each of them is normally formed by a substantiallycircumferential annular insert on which at least one filling insert isapplied, in a radially outer position thereof. Such annular inserts arecommonly identified as “bead cores” and have the task of keeping thetyre firmly fixed to the anchoring seat specifically provided in the rimof the wheel, thus preventing, in operation, the radially inner end edgeof the tyre from coming out from such a seat.

Specific reinforcing structures having the function of improving thetorque transmission to the tyre can be provided at the beads.

A crown structure is associated in a radially outer position withrespect to the carcass structure.

The crown structure comprises a belt structure and, in a radially outerposition with respect to the belt structure, a tread band made ofelastomeric material.

The belt structure comprises one or more belt layers arranged radiallyone on top of the other and having textile or metallic reinforcing cordswith a crossed orientation and/or an orientation substantially parallelto the direction of circumferential extension of the tyre.

A layer of elastomeric material, called “under-belt”, can be providedbetween the carcass structure and the belt structure, said layer havingthe function of making the radially outer surface of the carcassstructure as uniform as possible for the subsequent application of thebelt structure.

A so-called “under-layer” made of elastomeric material can be arrangedbetween the tread band and the belt structure, the under-layer havingproperties suitable for ensuring a steady union of the tread band to thebelt structure.

Respective sidewalls of elastomeric material are applied on the sidesurfaces of the carcass structure, each extending from one of the sideedges of the tread band up to the respective annular anchoring structureto the beads.

WO 2016/067192, to the same Applicant, discloses a process and anapparatus for applying a noise-reducing element to a tyre for vehiclewheels. The noise-reducing element is arranged on a first conveyor beltmoved along a feeding direction and having, on an upper surface thereof,a continuous film which supports a layer of adhesive material. Thenoise-reducing element is subsequently pressed against the continuousfilm so as to make it firmly adhere to a portion of the layer ofadhesive material. By means of the movement of the first conveyor beltalong the feeding direction, the noise-reducing element is subsequentlytransferred to a second conveyor belt arranged downstream of the firstconveyor belt along the aforementioned feeding direction. During suchtransfer, the continuous film is held at the first conveyor belt and, assoon as the noise-reducing element has left the first conveyor belt, theportion of layer of adhesive material that adheres to the noise-reducingelement is detached from the layer of adhesive material which is on thefirst conveyor belt. The detachment can take place as a consequence ofthe relative movement of the second conveyor belt with respect to thefirst conveyor belt (in the case in which the adhesive material has weakinternal bonds) or through the cutting action exerted by a suitableblade provided between the two conveyor belts (in the case in which theadhesive material has very strong internal bonds). The noise-reducingelement is finally picked from the second conveyor belt up andpositioned in a predetermined position on a radially inner surface ofthe tyre.

The Applicant observes that the invention described in WO 2016/067192makes it possible to obtain a high automation of the gluing process ofthe noise-reducing elements to the tyres, thus obtaining an increasedproductivity of the lines dedicated to manufacturing of tyres providedwith noise-reducing elements.

The Applicant has considered the problem of obtaining a further increasein productivity in combination with the repeatability of the operationsof adhesion of a layer of adhesive material to each noise-reducingelement.

The Applicant has found that by aligning and compacting thenoise-reducing elements before the layer of adhesive material isarranged on each of them, and in particular by suitably manipulating thesingle noise-reducing elements acting at least in two directions tobring them substantially automatically to the aforementioned mutualalignment and compacting condition, and by suitably moving the singlenoise-reducing elements along their own feeding direction after havingapplied the respective layer of adhesive material onto each of them, itis possible to obtain a clean and precise detachment of the layer ofadhesive material adhered to a noise-reducing element from the oneadhered to a immediately subsequent noise-reducing element along thefeeding direction of the noise-reducing elements. In this way, theproductivity is further increased and the repeatability in thedistribution of adhesive layer on each noise-reducing element isobtained.

The present invention therefore relates, in a first aspect thereof, to aprocess for applying noise-reducing elements to a tyre for vehiclewheels.

Preferably, a plurality of noise-reducing elements is arranged,preferably spaced apart from one another, on a feeding belt movablealong a predetermined feeding direction.

Preferably, at least two of said noise-reducing elements are alignedalong said feeding direction.

Preferably, said at least two noise-reducing elements are brought intomutual contact along said feeding direction.

Preferably, said at least two noise-reducing elements are transferredfrom said feeding belt onto a service plane arranged downstream of saidfeeding belt along said feeding direction and having, on an uppersurface thereof, a continuous film which supports a layer of adhesivematerial.

Preferably, said layer of adhesive material is applied onto a lowersurface of each of said at least two noise-reducing elements taking itfrom said continuous film.

Preferably, said at least two noise-reducing elements are transferredone by one from said service plane to a conveyor belt arrangeddownstream of said service plane along said feeding direction.

Preferably, said at least two noise-reducing elements are positioned oneby one onto a radially inner surface of a tyre.

The Applicant believes that the aforementioned method, producing a cleanand precise detachment of the layer of adhesive material adhered to twonoise-reducing elements arranged in succession along the feedingdirection thereof thanks to the prior alignment and compacting of thenoise-reducing elements along the aforementioned feeding direction,effectively solves the aforementioned problems regarding theproductivity of the production lines dedicated to manufacturing tyresprovided with noise-reducing elements, at the same time obtaining therepeatability of the distribution operations of the layer of adhesivematerial on each noise-reducing element.

In a second aspect thereof, the present invention relates to anapparatus for applying noise-reducing elements to a tyre for vehiclewheels.

Preferably, a feeding belt is provided, the feeding belt beingconfigured to feed noise-reducing elements movable along a predeterminedfeeding direction.

Preferably, a first pushing element is provided, the first pushingelement being movable along a direction perpendicular to said feedingdirection to align at least two of said noise-reducing elements alongsaid feeding direction.

Preferably, a second pushing element is provided, the second pushingelement being movable along said feeding direction to bring said atleast two noise-reducing elements in mutual contact along said feedingdirection.

Preferably, a service plane is arranged downstream of said feeding beltalong said feeding direction, the service plane having, on an uppersurface thereof, a continuous film which supports a layer of adhesivematerial.

Preferably, said continuous film is movable along said feedingdirection.

Preferably, a pressing member is provided, the pressing member beingconfigured to press said at least two noise-reducing elements againstthe upper surface of said service plane so that said at least twonoise-reducing elements firmly adhere to a portion of said layer ofadhesive material.

Preferably, a conveyor belt is arranged downstream of said service planealong said feeding direction.

Preferably, said conveyor belt is movable along said feeding direction.

Preferably, a gripping member is provided, the gripping member beingconfigured to pick said at least two noise-reducing elements up and toposition them on a radially inner surface of a tyre.

The apparatus described above allows the method described above to becarried out.

The present invention can have, in at least one of the aforementionedaspects, at least one of the preferred features described hereinafter.

Preferably, arranging said plurality of noise-reducing elements on saidfeeding belt comprises positioning one after the other saidnoise-reducing elements on a loading belt arranged upstream of saidfeeding belt along said feeding direction. Said noise-reducing elementscan advantageously be positioned on said loading belt substantiallyrandomly, i.e. not only spaced apart but also without being perfectlyaligned, so as not to cause any slowing of the productivity of the line.The desired alignment and mutual positioning is indeed obtainedautomatically subsequently.

Preferably, during or after positioning said noise-reducing elements onsaid loading belt and before aligning said at least two noise-reducingelements said loading belt is moved along said feeding direction whilekeeping said feeding belt stationary.

Preferably, the movement of said loading belt proceeds until an endportion of a first noise-reducing element of said at least twonoise-reducing elements is arranged above said feeding belt.

Preferably, said loading belt and said feeding belt are subsequentlymoved in synchrony along said feeding direction until said firstnoise-reducing element is entirely arranged above said feeding belt. Inthis way, the automatic transfer of each of the noise-reducing elementsfrom the loading belt to the feeding belt is obtained.

Preferably, aligning said at least two noise-reducing elements comprisespushing said at least two noise-reducing elements in abutment against areference wall parallel to said feeding direction.

Preferably, said reference wall is associated with said feeding belt.

Preferably, said at least two noise-reducing elements have apredetermined width.

Preferably, said at least two noise-reducing elements have apredetermined length.

Preferably, aligning said at least two noise-reducing elements comprisespushing said at least two noise-reducing elements against said referencewall through a first pushing element which is moved, in a directionperpendicular to said feeding direction, with a predetermined strokedefined as a function of the width of said at least two noise-reducingelements. The length of the stroke carried out by the aforementionedfirst pushing element along the aforementioned direction perpendicularto the feeding direction is therefore adjustable depending on the widthof the noise-reducing elements which are processed, so as to obtain thedesired alignment of the noise-reducing elements without at the sametime deforming them excessively.

Preferably, said at least two noise-reducing elements are brought intomutual contact while they are kept aligned along said feeding direction.

The Applicant believes that such a provision makes it possible to obtainan optimal mutual positioning of the noise-reducing elements, suchoptimal mutual positioning allowing an optimal detachment of the layerof adhesive material adhered to a noise-reducing element from the oneadhered to the immediately subsequent noise-reducing element along thefeeding direction of the noise-reducing elements.

The Applicant also believes that the provision of compacting thenoise-reducing elements after they have been aligned (and therefore ofaligning the noise-reducing elements before they are brought into mutualcontact along the feeding direction) makes it possible to ensure thatthe desired mutual positioning of the noise-reducing elements isobtained irrespective of the material from which they are made. TheApplicant indeed believes that in the case in which the noise-reducingelements are made of a material having a high friction coefficient, itmay not be possible to obtain a perfect alignment of possiblenoise-reducing elements which are already compacted. This is because theaforementioned friction coefficient would lead the noise-reducingelements to move in an unpreventable manner when the first pushingelement is moved away from them after the alignment operation.

Preferably, said at least two noise-reducing elements are brought intomutual contact while said feeding belt and said continuous film arestationary.

Preferably, bringing said at least two noise-reducing elements intomutual contact comprises pushing a first noise-reducing element of saidat least two noise-reducing elements against a second noise-reducingelement of said at least two noise-reducing elements, said secondnoise-reducing element being arranged on said feeding belt downstream ofsaid first noise-reducing element.

Preferably, said first noise-reducing element is pushed against saidsecond noise-reducing element through a second pushing element which ismoved along said feeding direction with a predetermined stroke definedas a function of the length of said at least two noise-reducingelements. The length of the stroke carried out by the aforementionedsecond pushing element along the feeding direction is thereforeadjustable depending on the length of the noise-reducing elements whichare processed, so as to obtain the desired mutual contact of thenoise-reducing elements without at the same time deforming themexcessively.

Preferably, said first noise-reducing element is pushed against saidsecond noise-reducing element after said second noise-reducing elementhas been aligned and brought into contact with a third noise-reducingelement which is at least partially arranged on said service plane. Inthis way, the third noise-reducing element, being located in part abovethe service plane and thus having a layer of adhesive material adheredboth onto the lower face and onto the continuous film supported by theservice plane, does not move along the feeding direction because of thepushing action exerted by the first reducing element against the secondnoise-reducing element (and by the latter against the thirdnoise-reducing element). The third noise-reducing element thus acts asan abutment element against the pushing action exerted by the firstpushing element against the second noise-reducing element, allowing anoptimal compacting to be obtained between first noise-reducing elementand second noise-reducing element.

Preferably, said second noise-reducing element is aligned and broughtinto contact directly against said third noise-reducing element.

Alternatively, said second noise-reducing element is aligned and broughtinto contact with said third noise-reducing element throughinterposition of one or more further noise-reducing elements previouslyaligned and brought into mutual contact along said feeding direction.

Preferably, transferring said at least two noise-reducing elements fromsaid feeding belt onto said service plane comprises moving said feedingbelt and said continuous film in synchrony along said feeding direction.

Preferably, applying said layer of adhesive material comprises pressingsaid at least two noise-reducing elements against the upper surface ofsaid service plane.

Preferably, transferring one by one said at least two noise-reducingelements from said service plane to said conveyor belt comprises movingsaid continuous film and said conveyor belt in synchrony along saidfeeding direction until said first noise-reducing element is at leastpartially arranged above said conveyor belt.

Preferably, after the aforementioned synchronous movement said conveyorbelt is moved along said feeding direction while keeping said continuousfilm stationary. In this way, a detachment of the noise-reducing elementpositioned each time on the conveyor belt from those positioned on theservice plane is obtained.

Preferably, after having transferred said at least two noise-reducingelements to said conveyor belt and before positioning said at least twonoise-reducing elements on said tyre, said at least two noise-reducingelements are transferred one by one to an unloading belt arrangeddownstream of said conveyor belt along said feeding direction.

Preferably, the transfer of said at least two noise-reducing elements tosaid unloading belt is obtained as a consequence of the synchronousmovement of said conveyor belt and of said unloading belt along saidfeeding direction.

Preferably, after having transferred each noise-reducing element to saidunloading belt and before positioning said at least two noise-reducingelements on said tyre, said unloading belt is moved along said feedingdirection while keeping said conveyor belt stationary. Such a provisionmakes it possible to sufficiently move each noise-reducing element awayfrom the one which is immediately subsequent, so as to allow thenoise-reducing element to be picked up for the subsequent positioning onthe tyre without risking to accidentally bump the immediately subsequentnoise-reducing element along the feeding direction.

Preferably, the position of said continuous film on the upper surface ofsaid service plane along the direction perpendicular to said feedingdirection can be adjusted. Such a provision makes it possible to keepthe continuous film, and consequently the layer of adhesive materialsupported by it, in a centered position depending on the position takenu by the noise-reducing elements on the feeding belt along theaforementioned perpendicular direction after the alignment andcompacting operations.

Preferably, the speed of said feeding belt can be adjusted as a functionof the advancing speed of said continuous film on said service plane. Inthis way, it is possible to obtain the desired compacting of thenoise-reducing elements irrespective of the advancing speed of thecontinuous film. In particular, it is ensured that the speed of thefeeding belt is always slightly greater than that of the continuousfilm.

Preferably, said second pushing element is movable both along saidfeeding direction and along a vertical direction. The movement along thefeeding direction allows the aforementioned compacting of thenoise-reducing elements. The movement along the vertical direction makesit possible to periodically take the second pushing element into anout-of-bulk position after having compacted some of the noise-reducingelements and before compacting further noise-reducing elements.

Preferably, a loading belt where the noise-reducing elements are loadedis arranged upstream of said feeding belt along said feeding direction.The operator can position the noise-reducing elements on such a loadingbelt without paying particular attention to their mutual positioning.

Preferably, an unloading belt from where the noise-reducing elements areunloaded is arranged downstream of said conveyor belt along said feedingdirection. The provision of such an unloading belt allows each noisereducing element to be gripped automatically for being then positionedon the tyre, without risking to accidentally contact the subsequentnoise-reducing element along the feeding direction.

Preferably, said service plane comprises a central portion arrangedbelow said pressing member.

Preferably, said service plane comprises a tail portion mechanicallydisengaged from the central portion and arranged upstream of saidcentral portion along said feeding direction.

Preferably, said service plane comprises a head portion mechanicallydisengaged from the central portion and arranged downstream of saidcentral portion along said feeding direction.

Advantageously, the provision of three portions mechanically disengagedfrom one another allows the adjustment of the position of the headportion and/or the tail portion with respect to the central portion.Such a provision is useful for allowing the adjustment of the positionof the continuous film with respect to the position of thenoise-reducing elements depending for example on the dimensions of thenoise-reducing elements being used each time.

Preferably, an unwinding reel configured to unwind said continuous filmis arranged under said service plane at said tail portion.

Preferably, a winding reel configured to wind said continuous film isarranged under said service plane at said head portion.

Preferably, said continuous film extends from said unwinding reel tosaid winding reel passing over said tail portion, said central portionand said head portion of said service plane.

Preferably, an adjusting device for adjusting the position of saidcontinuous film on the upper surface of said service plane in adirection perpendicular to said feeding direction is provided.

Preferably, said adjusting device comprises at least one actuator deviceacting on said head portion and/or tail portion of said service plane tomove said head portion and/or tail portion with respect to said centralportion in a direction perpendicular to said feeding direction.

Preferably, first adjusting members configured to adjust the stroke ofsaid first pushing element are provided.

Preferably, second adjusting members configured to adjust the stroke ofsaid second pushing element are provided.

Preferably, third adjusting members configured to adjust the stroke ofsaid pressing member are provided.

Each of the aforementioned stroke adjusting members makes it possible toset the optimal stroke of the respective pushing/pressing members as afunction of the dimensions of the noise-reducing elements being usedeach time.

Further features and advantages of the present invention will becomeclearer from the following detailed description of preferred embodimentsthereof, made with reference to the attached drawings.

In such drawings:

FIG. 1 is a schematic side view of an exemplifying embodiment of anapparatus for automatically applying noise-reducing elements to a tyrefor vehicle wheels in accordance with the present invention, such anapparatus being illustrated in a first operative configuration thereof;

FIG. 2 is a schematic view from above of the apparatus of FIG. 1 ;

FIGS. 3-5 are simplified schematic side views of the apparatus of FIG. 1in two further operative configurations thereof;

FIG. 6 is a simplified schematic view from above of the apparatus ofFIG. 1 in the operative configuration of FIG. 5 ;

FIGS. 7 and 8 are simplified schematic side views of the apparatus ofFIG. 1 in further operative configurations thereof;

FIG. 9 is a simplified schematic view from above of the apparatus ofFIG. 1 in the operative configuration of FIG. 8 ;

FIG. 10 is a schematic perspective view of a portion of the apparatus ofFIG. 1 ;

FIG. 11 is a schematic view from above of a detail of the portion ofFIG. 10 ;

FIG. 12 is a schematic perspective view of a section of a tyre forvehicle wheels on the inner surface of which a plurality ofnoise-reducing elements have been glued, through the apparatus of FIG. 1.

In FIGS. 1-9 , reference numeral 1 wholly indicates an exemplifyingembodiment of an apparatus for automatically applying one by one aplurality of noise-reducing elements 100 on a radially inner surface 501of a tyre 500 for vehicle wheels, in accordance with the presentinvention.

An example of such a tyre is illustrated in FIGS. 2 and 12 and isindicated with 500. Preferably, it is a tyre for four-wheeled vehicles,more preferably for high-performance vehicles.

As illustrated in FIG. 12 , the noise-reducing elements 100 are gluedalong the circumferential direction of the tyre 500, preferablysymmetrically with respect to an axial middle plane M of the tyre 500.

FIG. 2 illustrates a further tyre, indicated with 600, on which it isforeseen to glue the noise-reducing elements 100, again through theapparatus 1 described herein, once the process of gluing thenoise-reducing elements 100 onto the tyre 500 is complete.

The tyres 500 and 600 are preferably arranged on a roller conveyor belt700 arranged close to the apparatus 1.

During the gluing operations, the tyre 500 on which the noise-reducingelements 100 are glued is held in position on the roller conveyor belt700 by suitable holding members 710. In the specific example illustratedherein, such a holding members 710 are vertically movable with respectto the roller conveyor belt 700 and are uniformly distributed around thetyre 500, so as to also obtain the centering of the tyre 500 withrespect to the aforementioned holding members 710. In particular, in theexample of FIG. 2 there are six holding members 710 equally spacedangularly by 60°.

The noise-reducing elements 100 preferably have a rectangularparallelepiped shape. More preferably, they have a width comprisedbetween about 100 mm and about 250 mm, a length comprised between about100 mm and about 300 mm and a thickness comprised between about 15 mmand about 50 mm. However, noise reducing elements 100 can have shapesand sizes different from those indicated herein.

As illustrated in FIG. 12 , preferably the noise-reducing elements 100are glued onto the radially inner surface 501 of the tyre 100 along thecircumferential direction of the latter, arranging the longer sides ofthe noise-reducing elements 100 substantially parallel to the axialmiddle plane M of the tyre 100.

Preferably, the mutual positioning of the noise-reducing elements 100 onthe radially inner surface 501 of the tyre 100 is such as to leave a gapbetween two adjacent noise-reducing elements 100. However, noisereducing elements 100 can be in direct mutual contact as well.

Preferably, the circumferential extension of the portion of radiallyinner surface 501 of the tyre 500 on which the noise-reducing elements100 are glued (hereinafter reference will be made to such acircumferential extension using the term “coverage”) is equal to atleast 50% of the circumferential extension of the radially inner surface501 of the tyre 500. Depending on the circumferential size of the tyre100, the aforementioned coverage can for example be comprised betweenabout 65% and about 95%, preferably between about 70% and about 90% ofthe circumferential extension of the radially inner surface 501 of thetyre 500. As the circumferential size of the tyre 500 varies it ispossible, if necessary, to use noise-reducing elements 100 of differentlength to obtain the desired coverages.

The noise-reducing elements 100 are preferably made of sound-absorbingporous material, for example expanded polymeric material, preferablyopen-cell foamed polyurethane. However, a different material havingsimilar capability to reduce noise can be used as well.

The density of the noise-reducing elements 100 is preferably comprisedbetween about 20 Kg/m³ and about 200 Kg/m³. In a specific embodiment,such a density is equal to about 40 Kg/m³.

With particular reference to FIGS. 1-10 , the apparatus 1 comprises aservice plane 10 on the upper surface 10 a of which (FIG. 10 ) acontinuous film 5 which supports a layer of adhesive material 5 a,preferably of the pressure-sensitive type, extends.

The service plane 10 comprises a head portion 10′, a tail portion 10″and a central portion 10′″. The head portion 10′ is arranged upstream ofthe central portion 10′″ along the feeding direction A. The tail portion10″ is arranged downstream of the central portion 10′″ along the feedingdirection A.

The head 10′ and tail 10″ portions are mechanically disengaged from thecentral portion 10′″, so as to be movable with respect to the centralportion 10′″ upon command of respective actuator devices 11, 12. Such aprovision makes it possible to adjust the position of the continuousfilm 5 on the upper surface 10 a of the service plane 10 in a directionperpendicular to the feeding direction A, as described below.

Preferably, the continuous film 5 is made of or coated with a non-stickmaterial. For example, at least one face of the continuous film 5 (inparticular at least the face opposite the one which is in contact withthe upper surface 10 a of the service plane 10) is made non-stickthrough a surface treatment with silicones.

The continuous film 5 is initially collected in an unwinding reel 5′preferably arranged below the service plane 10 close to the tail portion10′ thereof. The continuous film 5 extends from the unwinding reel 5′passing over the upper surface 10 a of the service plane 10 until awinding reel 5″ is reached. The winding reel 5″ is preferably arrangedbelow the service plane 10 close to the head portion 10″ thereof.

During the unwinding from the unwinding reel 5′, the continuous film 5is moved on the upper surface 10 a of the service plane 10 along thefeeding direction A to then be collected on the winding reel 5″.

The movement of the continuous film 5 along the feeding direction A iscontrolled by a drive member 51 associated with the unwinding reel 5′and by a drive member 52 associated with the unwinding reel 5″. Suchmovement is adjustable through respective speed adjusting devices 51 a,52 a associated with the aforementioned drive members 51, 52.

With reference to FIGS. 1-9 , the apparatus 1 further comprises,upstream of the service plane 10 with reference to the feeding directionA, a feeding belt 20 also movable along a feeding direction A. Themovement of the feeding belt 20 along the feeding direction A iscontrolled by a suitable drive member 220 (FIG. 2 ). The advancing speedof the feeding belt 20 along the feeding direction A is adjustablethrough a speed adjusting device 221 associated with the drive member220.

The apparatus 1 further comprises, downstream of the service plane 10with reference to the feeding direction A, a conveyor belt 30, alsomovable along a feeding direction A. The movement of the conveyor belt30 along the feeding direction A is controlled by a suitable drivemember 230 (FIG. 2 ). The advancing speed of the conveyor belt 30 alongthe feeding direction A is adjustable through a speed adjusting device231 associated with the drive member 230.

Preferably, in the exemplifying embodiment illustrated herein, a loadingbelt 40 where the noise-reducing elements 100 are loaded is providedupstream of the feeding belt 20 with reference to the feeding directionA. The loading belt 40 is also movable along the feeding direction A.The movement of the loading belt 40 along the feeding direction A iscontrolled by a suitable drive member 240 (FIG. 2 ). The advancing speedof the loading belt 40 along the feeding direction A is adjustablethrough a speed adjusting device 241 associated with the drive member240. An encoder (not illustrated) is associated with the loading belt40, preferably at a head portion thereof, to control the movement of theloading belt 40 along the feeding direction A.

Preferably, in the exemplifying embodiment illustrated herein, anunloading belt 50 from where the noise-reducing elements 100 areunloaded is provided downstream of the conveyor belt 30 with referenceto the feeding direction A. The unloading belt 50 is also movable alongthe feeding direction A. The movement of the unloading belt 50 along thefeeding direction A is controlled by a suitable drive member 250 (FIG. 2). The advancing speed of the unloading belt 50 along the feedingdirection A is adjustable through a speed adjusting device 251associated with the drive member 250.

The service plane 10 and the belts 20, 30, 40 and 50 are aligned, andarranged one after the other in accordance with what is described above,along the feeding direction A.

The adjusting devices 51 a, 52 a, 221, 231, 241, 251 act selectively onthe respective drive members 51, 52, 220, 230, 240, 250 independentlyfrom one another so as to be able to move the continuous film 5 and thebelts 20, 30, 40, 50 independently from one another and possibly atdifferent speeds, if necessary or desired.

In the attached figures:

-   -   reference numeral 100 a indicates, in FIGS. 1 and 2 , a        noise-reducing element 100 about to pass from the loading belt        40 to the feeding belt 20 and, in FIGS. 6-9 , the aforementioned        noise-reducing element 100 a when it is entirely arranged on the        feeding belt 20;    -   reference numeral 100 b indicates a noise-reducing element 100        arranged on the feeding belt 20 downstream of the noise-reducing        element 100 a along the feeding direction A;    -   reference numeral 100 c indicates a noise-reducing element 100        already transferred onto the service plane 10 while the        noise-reducing elements 100 a and 100 b are in the positions        described above;    -   reference numeral 100 d indicates a noise-reducing element 100        arranged between the noise-reducing element 100 b and the        noise-reducing element 100 c.

In the specific example illustrated herein, the noise-reducing elements100 are positioned on the loading belt 40 to be subsequently transferredto the feeding belt 20.

Beforehand, the noise-reducing elements 100 are picked up, manually byan operator, or automatically through a robotized arm (not illustrated),from a suitable tank (not illustrated) or, alternatively, cutting themfrom a sheet of large dimensions (for example 800×1200 mm) positionedclose to the loading belt 40.

The noise-reducing elements 100 are then positioned on the loading belt40, manually or through the aforementioned robotized arm, so that eachnoise-reducing element 100 positioned on the loading belt 40 is spacedfrom the noise-reducing element 100 previously positioned on the loadingbelt 40.

The passage of the noise-reducing elements 100 from the loading belt 40to the feeding belt 20 takes place as a consequence of the movement ofthe loading belt 40 and of the feeding belt 20 along the feedingdirection A. In particular, each noise-reducing element 100 arranged onthe loading belt 40 is firstly moved towards the feeding belt 20 as aconsequence of the movement of the loading belt 40 along the feedingdirection A, while keeping the feeding belt 20 stationary until a headportion of the noise-reducing element 100 is arranged above the feedingbelt 20. Thereafter, the movement of the loading belt 40 stops and onlythe feeding belt 20 moves along the feeding direction A until the entirenoise-reducing element 100 is arranged above the feeding belt 20.

Once positioned on the feeding belt 20, the noise-reducing elements 100are subject to an alignment and compacting operation, as describedhereinafter.

The noise-reducing elements 100 subsequently pass from the feeding belt20 to the service plane 10.

The passage of the noise-reducing elements 100 from the feeding belt 20to the service plane 10 takes place as a consequence of the synchronousmovement of the feeding belt 20 and of the continuous film 5 along thefeeding direction A.

Following the transfer of the noise-reducing elements 100 on the serviceplane 10, their lower face is made to adhere firmly to a portion of thelayer of adhesive material 5 a provided on the upper face of the portionof continuous film 5 arranged on the upper surface 10 a of the serviceplane 10. In particular, the portion of layer of adhesive material 5 athat is located below each noise-reducing element 100 attaches firmly tothe lower face of the noise-reducing element 100 and remains attached tosuch a noise-reducing element 100 during the subsequent movement of thecontinuous film 5 along the feeding direction A. Therefore, the portionof continuous film 5 wound on the winding reel 5″ is substantially freeof the aforementioned layer of adhesive material 5 a.

The noise-reducing elements 100 subsequently pass from the service plane10 to the conveyor belt 30. Such a passage takes place as a consequenceof the synchronous movement of the continuous film 5 and of the conveyorbelt 30 along the feeding direction A. As soon as each noise-reducingelement 100 is arranged, preferably entirely, above the conveyor belt30, the latter is moved along the feeding direction A while keeping thecontinuous film 5 stationary, so as to obtain the clean and precisedetachment of the layer of adhesive material 5 a associated with thenoise-reducing element just transferred to the conveyor belt 30 from thelayer of adhesive material 5 a associated with the continuous film 5supported by the service plane 10.

The noise-reducing elements 100 subsequently pass from the conveyor belt30 to the unloading belt 50.

The passage of the noise-reducing elements 100 from the conveyor belt 30to the unloading belt 50 takes place as a consequence of the synchronousmovement of the conveyor belt 30 and of the unloading belt 50 along thefeeding direction A. As soon as each noise-reducing element 100 isarranged, preferably entirely, above the unloading belt 50, the latteris moved along the feeding direction A while keeping the conveyor belt30 stationary, so as to take the noise-reducing element 100 arranged onthe unloading belt 50 away from the one which is immediately subsequentand which is still arranged on the conveyor belt 30.

From what has been illustrated above, it can be seen that:

-   -   when the noise-reducing elements 100 pass from the loading belt        40 to the feeding belt 20 and, thereafter, from the latter to        the service plane 10, they are free of adhesive material;    -   when the noise-reducing elements 100 are on the service plane        10, a portion of the layer of adhesive material 5 a present on        the continuous film 5 supported by the service plane 10 adheres        to the lower face of each of the aforementioned noise-reducing        elements 100;    -   when the noise-reducing elements 100 pass from the service plane        10 to the conveyor belt 30 and, thereafter, from the latter to        the unloading belt 50, the aforementioned portion of layer of        adhesive material 5 a remains associated with the lower face of        each of the aforementioned noise-reducing elements 100.

The continuous film 5 is preferably made of a non-stick material (forexample paper or polymeric material like polyethylene PE, polypropylenePP or polyethylene terephthalate PET, whose surface is treated withsilicones). The adhesion force of the layer of adhesive material 5 a onthe continuous film 5 is therefore substantially lower than the adhesionforce of the layer of adhesive material 5 a on the lower face of thenoise-reducing elements 100.

Such a continuous film 5 has a width equal to or greater than that ofthe noise-reducing elements 100. Preferably, the possible difference inwidth between continuous film 5 and noise-reducing elements 100 is notgreater than about 2 mm.

The adhesive applied on the continuous film 5 preferably has a thickness(including the layer of adhesive material 5 a) comprised between 30 and250 μm, for example equal to about 80 μm.

Examples of continuous film 5 (provided with the layer of adhesivematerial 5 a) that can be used are: 300LSE and 9773 of 3M Company and5015T of Nitto Europe NV.

As illustrated in FIGS. 1-10 , above the central portion 10′″ of theservice plane 10 there is a pressing member 60 which can be periodicallymoved along a substantially vertical direction to press each time atleast some of the noise-reducing elements 100 which are above saidcentral portion 10′″ against the continuous film 5 supported by theservice plane 10, so as to ensure that each of such noise-reducingelements 100 can adhere firmly to the respective portion of layer ofadhesive material 5 a (FIG. 4 ).

As illustrated in FIG. 2 , the pressing element 60 is preferablycontrolled through actuation of a pneumatic cylinder 61. The pressureforce is adjustable through a pressure adjuster 62 and the pressing timecan also be set.

As illustrated in FIGS. 1-9 , the apparatus 1 comprises, at the feedingbelt 20, a first pushing element 300 which can be periodically movedalong a horizontal direction B (FIG. 6 ) perpendicular to the feedingdirection A.

The first pushing element 300 is configured to align along the feedingdirection A at least two noise-reducing elements 100 a, 100 b arrangedabove the feeding belt 20. Such alignment takes place by pushing said atleast two noise-reducing elements 100 a, 100 b through said firstpushing element 300 against a reference wall 310 associated with thefeeding belt 20 and extending parallel to the feeding direction A.

After the alignment has occurred, the noise-reducing elements 100 a, 100b remain aligned along the feeding direction A when they are transferredfrom the feeding belt 20 to the service plane 10 and, thereafter, to theconveyor belt 30 and to the unloading belt 50.

As illustrated in FIG. 2 , the first pushing element 300 is controlledby a drive member 301 that is in turn associated with an adjustingmember 302 configured to adjust the stroke of the first pushing element300 along the direction B as a function of the width of thenoise-reducing elements 100 being used each time.

Preferably, the movement of the first pushing element 300 along thedirection B is obtained through actuation of a pneumatic cylinder andits stroke is mechanically adjustable through the adjustment of contrastscrews (not illustrated).

The apparatus 1 also comprises, close to a tail portion of the feedingbelt 20, a second pushing element 400 periodically movable both along avertical direction C (FIG. 7 ) and along the feeding direction A (FIGS.8 and 9 ).

The second pushing element 400 is configured to bring the noise-reducingelements 100 a, 100 b into mutual contact along the feeding direction A,after such noise-reducing elements 100 a, 100 b have been brought intoabutment against said reference wall 310 by the first pushing element300.

The second pushing element 400 comprises a vertical plate 400 a intendedto push the noise-reducing element 100 a against the noise-reducingelement 100 b along the feeding direction A.

As illustrated in FIG. 1 , the second pushing element 400 is controlledby a drive member 401 which is in turn associated with an adjustingmember 402 configured to adjust the stroke of the second pushing element400 along the feeding direction A as a function of the length of thenoise-reducing elements 100 being used each time.

Preferably, the movement of the second pushing element 400 along thevertical direction C is obtained through actuation of a pneumaticcylinder. Such movement is controlled by a pair of magnetic end stops(not illustrated) applied directly onto such a pneumatic cylinder.

Preferably, the movement of the second pushing element 400 along thefeeding direction A is obtained through actuation of an electric motor.Such movement is adjusted, through the adjusting member 402, as afunction of the length of the noise-reducing elements 100 being used.

The apparatus 1 also comprises a plurality of first contrast rollers 450arranged at the tail portion 10′ of the service plane 10 and a pluralityof second contrast rollers 451 arranged at the head portion 10″ of theservice plane 10.

Preferably, the contrast rollers 450 are arranged above a head portionof the feeding belt 20 and extend up to above the tail portion 10′ ofthe service plane 10. They prevent the noise-reducing elements 100 tolift from the feeding belt 20 and from the service plane 10 because ofthe push exerted by the second pushing element 400 along the feedingdirection A during the compacting operations of the noise-reducingelements 100.

Preferably, the contrast rollers 451 are arranged above the head portion10″ of the service plane 10 and extend up to above a tail portion of theconveyor belt 30. They prevent the noise-reducing elements 100 to liftfrom the service plane 10 and from the conveyor belt 30 during thepassage from the service plane 10 to the conveyor belt 30.

In an embodiment that is not illustrated, a hot wire is arranged betweenthe service plane 10 and the conveyor belt 30, which in practice acts asa blade. Such a hot wire is movable, preferably along a substantiallyvertical direction, between a rest position, distal from the uppersurface 10 a of the service plane 10, and an operative position in whichthe hot wire intersects the upper surface 10 a of the service plane 10.

When it is in its rest position, the hot wire does not perform anyaction. On the other hand, when the hot wire is in its operativeposition, it cuts the layer of adhesive material 5 a arranged between afirst noise-reducing element 100 just transferred to the conveyor belt30 and the one which is associated with a second noise-reducing element100 adjacent to the aforementioned noise-reducing element 100 and aboutto be transferred from the service plane 10 to the conveyor belt 30,separating the layer of adhesive material 5 a associated with theaforementioned first noise-reducing element 100 from the layer ofadhesive material 5 a associated with the aforementioned secondnoise-reducing element 100.

The aforementioned embodiment can be used when the adhesive material 5 ahas very strong internal bonds.

In the embodiment illustrated in the attached drawings theaforementioned hot wire is not used. Such an embodiment can be used whenthe adhesive material 5 a used does not have very strong internal bonds.In this case, the detachment of the layer of adhesive material 5 aadhered to the noise-reducing element transferred to the conveyor belt30 from the layer of adhesive material 5 a associated with thenoise-reducing element 100 present on the service plane 10 only takesplace as a consequence of a variation of speed of the conveyor belt 30with respect to the continuous film 5 and thanks to the holding actionexerted on the service plane 10 by the pressure force exerted on thenoise-reducing element 100 by the pressing member 60.

The apparatus 1 also comprises, close to a head portion of the unloadingbelt 50, a gripping member which is preferably a robotized arm 80 of theanthropomorphous type having at least six axes and intended to pick thenoise-reducing elements 100 up from the loading belt 50 and to positionthem in the desired position on the radially inner surface 501 of thetyre 500. Such positioning can include applying a suitable pressure onthe radially inner surface 501 of the tyre 500.

The robotized arm 80 is preferably of the aerial type (i.e. it isconfigured to be associated with the ceiling or with an aerial beam) soas not to occupy space on the ground. However, a robotized armconstrained to the ground can also be used as an alternative.

The robotized arm 80 comprises an articulated linkage 81 that allows themovement of the robotized arm 80 along any direction in space.

At a free end thereof, the robotized arm 80 comprises a gripping member82 suitable for picking the noise-reducing elements 100 up from theunloading belt 50 and for holding them in position during the movementof the robotized arm 80 towards the tyre 500.

In an embodiment thereof, the gripping member 82 comprises a pluralityof suction channels (not illustrated) fluid-dynamically connected to asuction device capable to be selectively activated. Therefore, thegripping of the noise-reducing elements 100 from the unloading belt 50and their holding during the movement of the robotized arm 80 towardsthe tyre 500 takes place thanks to the suction force exerted on thenoise-reducing elements 100 once the aforementioned suction device hasbeen activated. The release of the noise-reducing elements 100 on theradially inner surface 501 of the tyre 500, on the other hand, takesplace following the deactivation of the aforementioned suction device.

The gripping member 82 comprises a gripping surface 82 a having a curvedprofile. Preferably, the profile of the gripping surface 82 a has aradius of curvature substantially equal to that of the inner surface 501of the tyre 500 along the circumferential direction thereof. Inparticular, the value of the radius of curvature of the gripping surface82 a is substantially equal to an average value of the radii ofcurvature of the inner surfaces of a batch of tyres 500, 600 on which itis wished to glue the noise-reducing elements 100.

Preferably, the gripping surface 82 a has substantially the sameextension as the one of the noise-reducing element 100.

In an alternative embodiment, the gripping member 82 can comprise aplurality of retractable hooks capable of being suitably controlled tocapture/release the noise-reducing elements 100.

With reference to FIG. 10 , the unwinding reel 5′ preferably comprises apneumatically-controlled spindle 5′a that, after a radial expansionthereof, allows a roll of continuous film 5 to be constrained inrotation on the spindle 5′a and the aforementioned roll to be locked inabutment against an abutment wall 5′b that lies on the same verticalplane on which the reference wall 310 lies.

Similarly, the winding reel 5″ preferably comprises apneumatically-controlled spindle 5″a that, through the radial expansionthereof, allows a collection roll of the continuous film 5 to beconstrained in rotation on the spindle 5″a and the aforementioned rollto be locked in abutment against an abutment wall 5″b also lying on thesame vertical plane on which the reference wall 310 lies.

The winding reel 5″ further comprises a disc 5″c fitted onto the spindle5″a and constrained on the latter in a position such as to preventmovements of the continuous film 5 with respect to the rotation axis ofthe spindle 5″a during the winding of the continuous film 5 on the rollmounted on the spindle 5″a. The position of the disc 5″c on the spindle5″a varies as the width of the noise-reducing elements 100 used on eachoccasion varies.

With reference to FIGS. 10 and 11 , the apparatus 1 further comprises anadjusting device 15 configured to adjust the position of the continuousfilm 5 on the upper surface 10 a of the service plane 10 in a directionperpendicular to the feeding direction A (i.e. along the aforementioneddirection B). Such a device 15 allows the correct centering of thecontinuous film 5 with respect to the noise-reducing elements 100arranged on the upper surface 10 a of the service plane 10.

The adjusting device 15 comprises a pair of photocells 15 a, 15 b thatdetect the position of a longitudinal edge of the continuous film 5within a tolerance range corresponding to the distance between the twophotocells 15 a, 15 b (equal for example to 1 mm). In the specificexample illustrated in FIG. 11 , the photocells 15 a, 15 b are arrangedat the winding reel 5″.

The adjusting device 15 further comprises an inclined roller 16 arrangedbetween the winding reel 5″ and the service plane 10. The inclination ofthe inclined roller 16 is modified when the photocells 15 a, 15 b detectthat the edge of the continuous film 5 is outside of the aforementionedtolerance range. The variation of inclination of the inclined roller 16results in a movement of the continuous film 5 along the aforementioneddirection perpendicular to the feeding direction A.

The inclined roller 16 is supported, at an end thereof, by a supportblock 16 a and, at the opposite end thereof, by an abutment block 16 b.

The abutment block 16 b comprises a pneumatic cylinder 16 c and anabutment element 16 d. The movement of the piston of the pneumaticcylinder 16 c with respect to the abutment element 16 d results in avariation of the inclination of the inclined roller 16. Photocellsanalogous to photocells 15 a, 15 b described above are provided at theunwinding reel 5′ to control the position of the continuous film 5before it passes on the upper surface 10 a of the service plane 10.

Further photocells analogous to photocells 15 a, 15 b described abovecan be provided at the upper surface of the service plane 10 to controlthe position of the continuous film 5 on such a surface along thedirection perpendicular to the feeding direction A.

The actuator devices 11 and 12 and the adjusting device 15 cooperate toobtain the centering of the continuous film 5 on the upper surface 10 aof the service plane 10 with respect to the noise-reducing elements 100arranged on such a surface. Such centering is therefore obtained thanksto the relative movement of the continuous film 5 and of the tail 10′and head 10″ portions of the service plane 10 with respect to thecentral portion 10′″ of the service plane 10.

A return roller 17 is arranged between the winding reel 5″ and theinclined roller 16. The return roller 17 is provided with an encoder todetect the peripheral speed of such a roller, corresponding to theadvancing speed of the continuous film 5 along the feeding direction A.The signal detected by the encoder is used to drive the rotation of thewinding reel 5″ so as to create a constant tension in the portion ofcontinuous film 5 arranged between the return roller 17 and the windingreel 5″. Such a signal is also used to adjust the speed of the feedingbelt 20, so as to drive this belt with a speed slightly higher than theadvancing speed of the continuous film 5, in order to avoid that thecompacted noise-reducing elements can move away from one another alongthe feeding direction A.

As illustrated in FIG. 1 , the apparatus 1 further comprises a pluralityof photocells, all indicated with 70, arranged between the loading belt40 and the feeding belt 20, between the latter and the conveyor belt 30and between the latter and the unloading belt 50, respectively, tointercept the passage of the noise-reducing elements 100 andconsequently drive the drive members 51, 52, 220, 230, 240, 250 so thatthe continuous film 5 and the belts 20, 30, 40 and 50 move along thefeeding direction A with the desired speed and timing.

A preferred embodiment of a process for automatically applying thenoise-reducing elements 100 to the tyre 500 will now be described. Inparticular, this process can be carried out by the apparatus 1 describedabove.

Initially, as illustrated in FIGS. 1 and 2 , the noise-reducing elements100 are positioned in sequence on the loading belt 40 so as to be spacedapart from one another.

The loading belt 40 is moved with a predetermined speed along thefeeding direction A. Such movement can take place sequentially andalternately with respect to the positioning of the noise-reducingelements 100 on the loading belt 40, each time with an advancing pitchhaving a predetermined length, or during a continuous movement of theloading belt 40 along the feeding direction A.

The positioning of the noise-reducing elements 100 on the loading belt40 can be carried out by a robotized arm or manually by an operator, asdescribed earlier.

The noise-reducing elements 100 are subsequently transferred from theloading belt 40 to the feeding belt 20. Such a transfer initially takesplace as a consequence of the movement of the loading belt 40 along thefeeding direction A with an advancing pitch of predetermined length,while keeping the feeding belt 20 stationary. When a head portion ofeach noise reducer 100 is arranged above the feeding belt 20, themovement of the loading belt 40 stops and only the feeding belt 20 movesalong the feeding direction A until the entire noise-reducing element100 is arranged above the feeding belt 20.

In this way the operative configuration illustrated in FIG. 3 isreached, in which a noise-reducing element 100 a has just beentransferred from the loading belt 40 to the feeding belt 20.

In such an operative configuration, the noise-reducing element 100 a isneither aligned with, nor in contact with, the noise-reducing element100 b previously transferred from the loading belt 40 to the feedingbelt 20.

The first pushing element 300 is then activated to obtain the alignmentof the noise-reducing elements 100 a and 100 b along the feedingdirection A and, subsequently, with the activation of the second pushingelement 400 to obtain the compacting of the noise-reducing elements 100a and 100 b along the feeding direction A (FIGS. 6-9 ).

The alignment and compacting operations are carried out while theloading 40 and feeding 20 belts are kept stationary.

The alignment comprises the activation of the first pushing element 300and its movement along the direction B until the noise-reducing elements100 a and 100 b are brought into abutment against the reference wall310. The stroke of the first pushing element 300 is defined as afunction of the width of the noise-reducing elements 100 being used.

The subsequent compacting is carried out while the pressing member 300is kept in the aforementioned pushing position against the referencewall 310 and comprises the activation of the second pushing element 400and its movement firstly along the vertical direction C and,subsequently along the feeding direction A (FIG. 7 ).

The movement of the second pushing element 400 along the verticaldirection C is carried out to position the vertical plate 400 a upstreamof the noise-reducing element 100 a along the feeding direction A.

The subsequent movement of the second pushing element 400 along thefeeding direction is carried out to push the noise-reducing element 100a along the feeding direction A until it is brought into contact againstthe noise-reducing element 100 b (FIGS. 8 and 9 ). The stroke of thesecond pushing element 400 along the feeding direction A is defined as afunction of the length of the noise-reducing elements 100 and is such asto generate a certain contact interference between the noise-reducingelement 100 a and the noise-reducing element 100 b. Such a provisionallows the noise-reducing elements 100 a and 100 b to stay in mutualcontact when, once compacting has occurred, the second pushing element400 is moved away from the noise-reducing element 100 a to proceed withthe subsequent operations described hereinafter.

The push exerted by the pressing member 400 on the noise-reducingelement 100 a causes the compacting of the noise-reducing element 100 aagainst the reducing element 100 b and against all of the noise-reducingelements arranged downstream of the noise-reducing element 100 b alongthe feeding direction A (and thus already compacted and aligned with thenoise-reducing element 100 b) and arranged on the service plane 10(between these there is the one indicated in the attached figures with100 c) and on the feeding belt 20 (between these there is the oneindicated in the attached figures with 100 d).

The noise-reducing elements 100, once aligned and compacted, aretransferred from the feeding belt 20 to the service plane 10 as aconsequence of the synchronous movement of the feeding belt 20 and ofthe continuous film 5 along the feeding direction A with an advancingpitch of predetermined length (preferably equal to the length of thenoise-reducing elements 100). The movement of the continuous film 5comprises the unwinding of a longitudinal portion of the continuous film5, provided with the layer of adhesive material 5 a, from the unwindingreel 5′ and the winding of a corresponding longitudinal portion of thecontinuous film 5, free of adhesive material 5 a, on the winding reel5″.

The noise-reducing elements 100 are subsequently pressed against theupper surface 10 a of the service plane 10 so that they can adherefirmly to the layer of adhesive material 5 a associated with thecontinuous film 5 arranged on the upper surface 10 a of the serviceplane 10 (FIGS. 4 and 5 ). Such pressure is exerted by activating thepressing member 60 arranged above the service plane 10, after havinginterrupted the movement of the continuous film 5 and of the feedingbelt 20 along the feeding direction A.

If necessary, the position of the continuous film 5 on the service plane10 in a direction perpendicular to the feeding direction A can besuitably adjusted through the adjusting device 15 described above, sothat the noise-reducing elements 100 that are positioned on thecontinuous film 5 are centered with respect to the latter along theaforementioned perpendicular direction.

The noise-reducing elements 100 are subsequently transferred from theservice plane 10 to the conveyor belt 30.

Such a transfer initially comprises the synchronous movement of thecontinuous film 5 and of the conveyor belt 30 along the feedingdirection A with an advancing pitch of predetermined length (preferablyequal to the length of the noise-reducing elements 100). Thereafter, inparticular as soon as each noise-reducing element 100 is at leastpartially arranged above the conveyor belt 30, only the conveyor belt 30moves along the feeding direction A with the aforementioned advancingpitch, while keeping the continuous film 5 stationary.

In this way, a desired spacing of the noise-reducing elements 100 isobtained on the conveyor belt 30, as shown in FIGS. 1 and 2 . Forexample, it is ensured that the noise-reducing elements 100 are mutuallyspaced apart on the conveyor belt 30 by a distance greater than about 1mm, preferably comprised between about 1 mm and about 3-5 mm.

If the internal bonds of the layer of adhesive material 5 a are not verystrong, the movement of the conveyor belt 30 with respect to thecontinuous film 5 also makes it possible to obtain a clean and precisedetachment of the layer of adhesive material 5 a associated with thenoise-reducing element 100 arranged on the conveyor belt 30 from thelayer of adhesive material 5 a associated with the continuous film 5that winds on the winding reel 5″.

If, on the other hand, the internal bonds of the layer of adhesivematerial 5 a are such as not to allow the aforementioned clean andprecise detachment, such detachment is obtained through the cuttingcarried out by the aforementioned hot wire. Advantageously, the movementof the conveyor belt 30 with respect to the continuous film 5 makes itpossible to sufficiently move the noise-reducing element 100 away fromthe noise-reducing material 100 about to be transferred from the serviceplane 10 to the conveyor belt 30, so as to prevent the hot wire fromaccidentally cut one or both of the aforementioned noise-reducingelements 100.

The noise-reducing elements 100 are subsequently transferred from theconveyor belt 30 to the unloading belt 50.

Such transfer initially comprises the synchronous movement of theconveyor belt 30 and of the unloading belt 50 along the feedingdirection A with a first advancing pitch of predetermined length.Thereafter, preferably as soon as each noise-reducing element 100 isentirely arranged above the unloading belt 50, only the unloading belt50 moves along the feeding direction A with a second advancing pitchgreater than or equal to the aforementioned first advancing pitch, whilekeeping the conveyor belt 30 stationary.

The noise-reducing elements 100 arranged on the unloading belt 50 aresubsequently picked in sequence up from the unloading belt 50 by therobotized arm 80 to be transferred towards the tyre 500 and positioned(and thus glued) at respective predetermined positions on the radiallyinner surface 501 of the latter. Such picking up and transferring iscarried out by the gripping member 82 of the robotized arm 80.

The picking of the noise-reducing elements 100 up from the unloadingbelt 50 and the holding thereof during the movement towards the tyre 500takes place thanks to the suction force exerted on the noise-reducingelements 100 by the gripping member 82 (FIGS. 1 and 3 ).

The aforementioned operations of picking the noise-reducing element 100up from the unloading belt 50 and gluing on the radially inner surface501 of the tyre 500 are repeated in sequence for a plurality ofnoise-reducing elements 100 until the desired coverage of the radiallyinner surface 501 of the tyre 500 is reached.

As illustrated in FIGS. 4 and 5 , the robotized arm 80, after havingdeposited a first noise-reducing element 100 on the tyre 500, is movedtowards the unloading belt 50 to pick up a second noise-reducing element100 that meanwhile has been moved along the feeding direction A untilthe picking up position previously taken up by the aforementioned noisereducing element has been reached.

The robotized arm can be configured to pick up the noise-reducingelement 100 along a first direction or along a second directionperpendicular to the first direction and to position such anoise-reducing element 100 on the radially inner surface 501 of the tyre500 with the larger dimension of the noise-reducing element 100 arrangedparallel to the circumferential direction of the tyre 500 (asillustrated in FIG. 12 ) or perpendicular to such a circumferentialdirection, depending on the size of the tyre being used each time.

Once the gluing operations of all of the noise-reducing elements 100 arecomplete, the tyre 500 is for example picked up by a suitable robotizedarm and replaced by the tyre 600.

The process described above is repeated identically to apply a pluralityof noise-reducing elements 100 on the radially inner surface of the tyre600.

The present invention has been described with reference to somepreferred embodiments. Different modifications can be brought to theembodiments described above, still remaining within the scope ofprotection of the invention, defined by the following claims.

1.-29. (canceled)
 30. An apparatus for applying noise-reducing elementsto a tyre for vehicle wheels, comprising: a feeding belt configured tofeed noise-reducing elements, said feeding belt being movable along apredetermined feeding direction; a first pushing element movable along adirection perpendicular to said feeding direction to align at least twoof said noise-reducing elements along said feeding direction by pushingsaid at least two noise-reducing elements in abutment against areference wall parallel to said feeding direction; a second pushingelement movable along said feeding direction to bring said at least twonoise-reducing elements into mutual contact along said feeding directionwhile said at least two noise-reducing elements are being pushed againstsaid reference wall by said first pushing element; a service planearranged downstream of said feeding belt along said feeding directionand having, on an upper surface thereof, a continuous film whichsupports a layer of adhesive material, said continuous film beingmovable along said feeding direction; a pressing member configured topress said at least two noise-reducing elements against the uppersurface of said service plane so that said at least two noise-reducingelements adhere firmly to a portion of said layer of adhesive material;a conveyor belt arranged downstream of said service plane along saidfeeding direction and movable along said feeding direction; and agripping member configured to pick up said at least two noise-reducingelements and to position said at least two noise-reducing elements on aradially inner surface of a tyre.
 31. The apparatus according to claim30, wherein said second pushing element is movable both along saidfeeding direction and along a vertical direction.
 32. The apparatusaccording to claim 31, further comprising a loading belt arrangedupstream of said feeding belt along said feeding direction.
 33. Theapparatus according to claim 32, further comprising an unloading beltarranged downstream of said conveyor belt along said feeding direction.34. The apparatus according to claim 33, wherein said service planecomprises: a central portion arranged below said pressing member; a tailportion mechanically disengaged from the central portion and arrangedupstream of said central portion along said feeding direction; and ahead portion mechanically disengaged from the central portion andarranged downstream of said central portion along said feedingdirection.
 35. The apparatus according to claim 34, further comprising:an unwinding reel configured to unwind said continuous film arrangedbelow said service plane at said tail portion; and a winding reelconfigured to wind said continuous film arranged below said serviceplane at said head portion, wherein said continuous film extends fromsaid unwinding reel to said winding reel passing over said tail portion,said central portion and said head portion of said service plane. 36.The apparatus according to claim 35, further comprising an adjustingdevice configured to adjust a position of said continuous film on theupper surface of said service plane in a direction perpendicular to saidfeeding direction.
 37. The apparatus according to claim 36, wherein saidadjusting device comprises at least one actuator device acting on saidhead portion and/or tail portion of said service plane to move said headportion and/or tail portion with respect to said central portion in adirection perpendicular to said feeding direction.
 38. The apparatusaccording to claim 37, comprising first adjusting members configured toadjust a stroke of said first pushing element.
 39. The apparatusaccording to claim 38, comprising second adjusting members configured toadjust a stroke of said second pushing element.
 40. The apparatusaccording to claim 39, comprising third adjusting members configured toadjust a stroke of said pressing member.